It is recognized within the electrical engineering community that power conversion of direct current (DC) to radio frequency (RF) power can be efficiently performed using active devices having dynamic characteristics that closely mimic that of switches. It is noted, however, that conventional switches dissipate power, which is an undesirable behavior.
A piezoelectric transistor is a new type of active electronic device, fabricated by mechanically coupling a piezoelectric actuator to a piezoresistive element. Since the actuation of a piezoelectric transistor is not defined by semiconductor band gap potential, a piezoelectric transistor may be operable at voltages much lower than that of conventional switches to help mitigate power dissipation.
However, piezoelectric transistors may not be readily suitable for power conversion applications (e.g., utilized in switching power amplifiers or other devices) because piezoelectric transistors do not possess intrinsic anti-parallel diodes that are beneficial in power conversion applications. Anti-parallel diodes are beneficial because if the load impedance of a power amplifier is non-ideal, and there are out-of-phase current, the presence of an anti-parallel diode may allow reverse current flow through the power amplifier without damaging reverse bias of the drain-source potential, permitting voltage clamping of the drain terminal and effectively serving as a self-protection mechanism.